<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Document</title>
</head>
<body>
    <form action="success.html">

用户名：<input type="" name="username" autocomplete="off"><br>
密码：<input type="password" name="password"><br>

单选框：<input type="radio" name="a" value="1" >
<input type="radio"  name="a" value="2" checked><br>
<!-- checked单选默认选中 -->
多选框：<input type="checkbox" name="b" value="1" >
<input type="checkbox" name="b" value="2" >
<input type="checkbox" name="b" value="3" ><br>
下拉列表：<select name="animal" >
    <option value="w">老虎</option>
    <option value="ww">兔子</option>
    <option value="www">猴子</option>
</select><br>
<input type="submit" value="登录"><br>
<button type="reset">重置</button>
<!-- type主要类型有：submit,reset,butto
    n,color,checkbox,radio,text,password,email 

autocomplete表单自动补全
readonly设置表单项只读数据会提交
disabled设置表单项禁用数据不会提交
autofocus设置表单项自动获取焦点-->
    </form>
</body>
</html>